I have a friend who has decided to try his hand at a marine tank. He has a aqua one 275. However he got the tank and didn't realise what was involved. He has set up the tank but he is not sure which way round you start the setting up (cycling process) of the tank eg does he add just the water while cycling then live sand after or does he do it straight away, does he get the live rocks while cycling or does this go in once the tank is fully cycles ect. Could somebody please shed some light on how he starts off. Also he is unsure on wether to get his water from the shop or get one of those reverse osmosis filters. Thanks

I think the best way to cycle a tank is by throwing a cocktail shrimp in as the ammonia source. This will start the process off and you can track it with a test kit. You will want to test ammonia, nitrite, and nitrate.
Cycling the tank makes the rock 'live' as the bacteria base is built up on them.
You want to make sure you are using ro/di water in the tank. If you make it yourself or buy it, that is up to him. I like to make it myself.

It depends on how much die off is on the rock. If the rock is clean, you won't have an adequate ammonia source for a strong bacteria colony. I don't think tossing in a 2 dollar shrimp would hurt.
I would put the water in first and get it to the proper salinity, then add the rock and sand and ammonia source if necessary.

Rock and sand must be in the tank when the ammonia is present. You want the bacteria to colonize their surfaces. Generally it takes a few weeks to a month to go through a normal cycle. Some try to speed it up with some bottled bacteria product, but I don't have first hand experience with this stuff to comment. It's certainly not necessary, since these products are new and the hobby has been around for a little while now.
So, rock, sand, and ammonia source (if necessary), all at once.
If you plan to use a shrimp during this process, it's good to put it in a mesh bag or similar so that it doesn't make a mess all over the place as it rots.